Hi Sandra,
yes, just increase the metamorph Scale to get higher density. This also makes the spines shorter, so increase Amount to get the right length. Unfortunately, the finer and longer the hair the slower it is, and with the need to render at high enough resolution for antialiasing, it's not practical to emulate long human hair. This applies for all these: Obelisky, Reedy, Hairpoly, Hairy, Obelisks, Bristler, Hairwave.